Re: hpcguix-web, channels, and inferiors

[Ricardo Wurmus <rekado@elephly.net>]

Ludovic Courtès <ludovic.courtes@inria.fr> writes:

> Ricardo Wurmus <rekado@elephly.net> skribis:
>
>> Ludovic Courtès <ludovic.courtes@inria.fr> writes:
>>
>>>> Yes I agree.  I wonder though: is there a way to know if a specific
>>>> derivation is a package?
>>>
>>> In general no.  Of course one could play trick to try and guess whether
>>> it corresponds to a package, but that should be avoided IMO.
>>
>> I wonder if we should work towards specifying a type for derivations.
>> This could be useful for the user interface to be able to clearly
>> distinguish grafts from full package builds.
>>
>> Currently, there’s no way to tell if the derivations listed under “These
>> derivations will be built” are expensive package builds or just simple
>> graft derivations.
>
> Indeed.  A simple trick would be to (ab)use the environment variable
> part of derivations as a property list, the way Nix has traditionally
> done it (see ‘user+system-env-vars’ in (guix derivations)).
>
> So we could have, say, a ‘hint’ environment variable, and the UI would
> use that to determine if it’s a graft.

This sounds like a good trick to me.  I think it would be great to give
more hints to the UI and make it clearer to users what work they can
expect Guix to perform.

--
Ricardo